This invention relates generally to an undercarriage sound reducing idler for track-type vehicles and more particularly to such an idler that has a resiliently mounted tread surface on the idler.
Environmental regulations, both in the United States and in other countries, are increasingly being directed to the suppression of noise emitted by construction equipment such as track-type tractors. In track-type tractors, the undercarriage, i.e., the track assemblies, support rollers, track tensioning assemblies, drive sprockets and idlers, are frequently a major contributor to the overall noise signature of track type equipment.
A great amount of effort has been directed to noise abatement strategies in undercarriage assemblies. For example, U.S. Pat. No. 3,937,528 issued Feb. 10, 1976 to Donald E. Clemens et al., titled SEGMENTED AND CUSHIONED IDLER FOR TRACK-TYPE VEHICLES AND METHOD FOR CARRYING SAME, and assigned to the Assignee of the present invention, describes a support idler directed to reducing the noise level of an endless track during operation of a vehicle. More specifically, Clemens at al. describes an idler having a plurality of arcuate segments circumferentially mounted about a peripheral flange of the idler hub and an elastomeric strip disposed between each of the arcuate segments and the peripheral flange. Each of the arcuate segments is mounted to the peripheral flange by a plurality of bolts. However, during vehicle operation, the elastomeric strips interposed between the arcuate segments and the peripheral flange are compressed during each rotation of the idler. The resultant resilient cyclic compression and recovery of the elastomeric strip during operation of the vehicle eventually results in relaxation of the bolt tension, or stretch, developed when mounting the arcuate segments on the hub flange. This may cause the attachment bolts to eventually loosen. The present invention is directed to overcoming such problems.
In accordance with one aspect of the present invention, a track-type vehicle has endless tracks mounted on opposite sides with an idler entrained within a forward portion of each of the endless tracks. The idler has hub with an annular flange and an endless chain resiliently mounted on the annular flange. The endless chain forms a rim that provides a substantially continuous peripheral bearing surface about the idler.
In another aspect of the present invention, a track-type vehicle idler is disposed for rotation about an axis of the idler and has a hub with an annular flange and an endless chain resiliently mounted on the annular flange. The resiliently mounted endless chain forms a rim that provides a substantially continuous peripheral bearing surface for an endless track supported by the idler.